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Nervous free will
Letters– A beef with driving From Colum Joyce There is a critical flaw in Chris Goodall’s idea that beef-eaters may be more polluting than gasguzzlers (11 August, p 20). The beef is in its disposal phase; the car is not. If you wish to compare carbon emissions you must take into account the entire life cycle carbon cost of the car, from raw material to disposal. You must of course also factor in what the driver had for lunch. Brussels, Belgium From Bernie Harris In the walker’s case, you need to calculate the carbon dioxide costs for their meals taken as a whole. It makes no sense to choose the beef, any more than it would to focus on the driver’s intake of potatoes or carrots, or indeed morning porridge. In the driver’s case, you need to include the portion of the lifetime CO2 costs of the car attributable to travelling 3 miles; the impact of
Akifumi Ogino and colleagues found that producing 1 kilogram of beef emits not 6 kilograms, but the equivalent of 36.4 kilograms of carbon dioxide, as we reported earlier (21 July, p 15). The calculations follow from that.
Time after time… From Hillary Shaw Living on a crowded island, I find the idea of our universe evolving into an empty, starless, bleak, cold nothingness – with odd little objects popping up occasionally – rather intriguing (18 August, p 26). As Mason Inman says, anything could emerge – a rock, a chair, even a brain. Wait long enough and maybe we’d get an entire planet Earth, complete with sun to warm it and other planets (as optional extras). Wait a really long time and we’d get all the stars in the heavens, too. Then someone in my office on a crowded island under those stars will be writing you a letter about how their universe will thin and empty, and odd little objects will pop up, like rocks, brains, another Earth, another sun… Newport, Shropshire, UK
Nervous free will
the production of the petrol used during that journey and, since cars traditionally require drivers, the costs of the driver’s calories, again taking account of their diet as a whole. Add that lot together and it is a pretty safe bet that driving 3 miles does indeed add more CO2 to the atmosphere than walking the same distance fuelled by beef. Oxford, UK The editor writes: ● As several readers have spotted, we introduced an error into Gudrun Freese’s letter. 24 | NewScientist | 1 September 2007
From John Hind When I think of “free will” I have the image of arriving at a fork in the road and taking a decision which is caused but not determined. Benjamin Libet’s 1983 experiment, as described by Chris Frith (11 August, p 46), does not seem to have any bearing on this, and I am baffled as to why so many neuroscientists and philosophers are seized by it. A subject whose brain is being monitored is instructed to “lift your finger whenever you feel the urge to do so”. What happens after this must hinge on how the brain unconsciously interprets this philosophically problematical but morally inconsequential instruction into something it can implement. The “whenever”
implies that the urge should be felt, but not immediately, while the danger of boredom discourages a lengthy delay. Within these constraints, this pseudo-decision has absolutely no consequence, so the only practical implementation involves self-programming to wait a random interval between, say, 5 seconds and a minute, and then deem the urge to have been felt. London, UK From Mark Vernon Frith only reports half the story about Libet’s free will experiments. Libet did indeed apparently show that the brain anticipates actions like bending a finger a split second before the person doing the bending is conscious of it – the observation that could undermine the concept of free will. He subsequently withdrew these conclusions when more subtle research showed that the same individual could also cancel the unconscious anticipation of the movement right up to the moment when it would have occurred. In short, conscious and unconscious elements of the action are part and parcel of the same event – just one of the complex features of free will that philosophers and theologians have been discussing for centuries. London, UK Chris Frith writes: ● I entirely agree with John Hind that, for example, the subject knows that Dr Libet will not be pleased if the urge to lift the finger never comes. Also, the decision may be inconsequential, but we are restricted in what sorts of experiments we can do. The key problem lies with the suggestion that something – and I would ask what – initiates both the motor action and the report of the urge to act. Would it be surprising if this something were quicker to cause the action than the report? Consider the other component of Libet’s 1983 experiment: on some trials subjects were asked to
indicate the time at which they lifted their finger, rather than the time at which they had the urge. They reported lifting their finger slightly earlier than the finger was actually lifted. I think Mark Vernon is referring to Libet’s idea of “free won’t”: that, although consciousness of will occurred after the relevant brain activity, the conscious decision to veto the action could still occur before the action occurred. Unfortunately, this conscious veto is also preceded by brain activity, so the problem remains.
Social free will From Alec Cawley We are social animals whose survival depends on living with a large group. One of the most important modules in our mind is associated with modelling our colleagues – who are also our rivals. In them, we see a mixture of predictable behaviour – we are all subject to gravity, for example, and no one can see through walls – and unpredictable. We call the latter free will. It matters not that this may be predictable at some deep physical level. At the level of everyday experience, it passes what could be called the duck test: it walks like free will, it quacks like free will, it is indistinguishable from free will. Then we turn that same module we use to model others to modelling ourselves. We have to do so in order to perform the high-order analysis that psychologists tell us we perform: www.newscientist.com
Akifumi Ogino and colleagues found that producing 1 kilogram of beef emits not 6 kilograms, but the equivalent of 36.4 kilograms of carbon dioxide, as we reported earlier (21 July, p 15). The calculations follow from that.
Time after time… From Hillary Shaw Living on a crowded island, I find the idea of our universe evolving into an empty, starless, bleak, cold nothingness – with odd little objects popping up occasionally – rather intriguing (18 August, p 26). As Mason Inman says, anything could emerge – a rock, a chair, even a brain. Wait long enough and maybe we’d get an entire planet Earth, complete with sun to warm it and other planets (as optional extras). Wait a really long time and we’d get all the stars in the heavens, too. Then someone in my office on a crowded island under those stars will be writing you a letter about how their universe will thin and empty, and odd little objects will pop up, like rocks, brains, another Earth, another sun… Newport, Shropshire, UK
Nervous free will
the production of the petrol used during that journey and, since cars traditionally require drivers, the costs of the driver’s calories, again taking account of their diet as a whole. Add that lot together and it is a pretty safe bet that driving 3 miles does indeed add more CO2 to the atmosphere than walking the same distance fuelled by beef. Oxford, UK The editor writes: ● As several readers have spotted, we introduced an error into Gudrun Freese’s letter. 24 | NewScientist | 1 September 2007
From John Hind When I think of “free will” I have the image of arriving at a fork in the road and taking a decision which is caused but not determined. Benjamin Libet’s 1983 experiment, as described by Chris Frith (11 August, p 46), does not seem to have any bearing on this, and I am baffled as to why so many neuroscientists and philosophers are seized by it. A subject whose brain is being monitored is instructed to “lift your finger whenever you feel the urge to do so”. What happens after this must hinge on how the brain unconsciously interprets this philosophically problematical but morally inconsequential instruction into something it can implement. The “whenever”
implies that the urge should be felt, but not immediately, while the danger of boredom discourages a lengthy delay. Within these constraints, this pseudo-decision has absolutely no consequence, so the only practical implementation involves self-programming to wait a random interval between, say, 5 seconds and a minute, and then deem the urge to have been felt. London, UK From Mark Vernon Frith only reports half the story about Libet’s free will experiments. Libet did indeed apparently show that the brain anticipates actions like bending a finger a split second before the person doing the bending is conscious of it – the observation that could undermine the concept of free will. He subsequently withdrew these conclusions when more subtle research showed that the same individual could also cancel the unconscious anticipation of the movement right up to the moment when it would have occurred. In short, conscious and unconscious elements of the action are part and parcel of the same event – just one of the complex features of free will that philosophers and theologians have been discussing for centuries. London, UK Chris Frith writes: ● I entirely agree with John Hind that, for example, the subject knows that Dr Libet will not be pleased if the urge to lift the finger never comes. Also, the decision may be inconsequential, but we are restricted in what sorts of experiments we can do. The key problem lies with the suggestion that something – and I would ask what – initiates both the motor action and the report of the urge to act. Would it be surprising if this something were quicker to cause the action than the report? Consider the other component of Libet’s 1983 experiment: on some trials subjects were asked to
indicate the time at which they lifted their finger, rather than the time at which they had the urge. They reported lifting their finger slightly earlier than the finger was actually lifted. I think Mark Vernon is referring to Libet’s idea of “free won’t”: that, although consciousness of will occurred after the relevant brain activity, the conscious decision to veto the action could still occur before the action occurred. Unfortunately, this conscious veto is also preceded by brain activity, so the problem remains.
Social free will From Alec Cawley We are social animals whose survival depends on living with a large group. One of the most important modules in our mind is associated with modelling our colleagues – who are also our rivals. In them, we see a mixture of predictable behaviour – we are all subject to gravity, for example, and no one can see through walls – and unpredictable. We call the latter free will. It matters not that this may be predictable at some deep physical level. At the level of everyday experience, it passes what could be called the duck test: it walks like free will, it quacks like free will, it is indistinguishable from free will. Then we turn that same module we use to model others to modelling ourselves. We have to do so in order to perform the high-order analysis that psychologists tell us we perform: www.newscientist.com